Saturday, September 13, 2008

Train drivers do not "fail to heed a stop signal"

There was a recent train crash in Los Angeles. A report just came out, and it claims that the reason for the accident is human error:

Friday's two-train collision killed 25 people and injured more than 130 others near Los Angeles after an engineer failed to heed a stop signal, a spokeswoman for Metrolink commuter trains said.

Ok, hold on now. Trains, or train conductors, do not "fail to heed a stop signal" and just run past red lights. For example, in subways, signals have something like a ski next to them on the ground by the track. When the signal is red, the ski raises. If the train runs past the red signal, then the ski pushes a lever on the train, and this forcefully activates the brakes thus stopping the formation. In other words, stop signals are driver-failure safe.

You can see this in action at NYC's and NJ's subways (and in Japan, and in Spain). The subways in Buenos Aires have the same feature. Ever wonder why no driver ever dares to run past a red signal, not even by an inch? Now you know why.

These mechanisms are well known, see here for a book published in 1915 talking about such devices. So now, how is it that human error on the part of an engineer or a driver can be the sole source of fault in the Los Angeles train crash? No my friend, there is more than that at play. For example:
  • Does the signal system have forceful braking measures to deal with trains which, for whatever reason, run past a red signal?
  • If the signal system includes forceful braking measures, why didn't they work?
Don't come tell me a single person committing a single mistake (such as text messaging) or perhaps having a sudden medical problem such as a heart attack can cause human life loss in large scale mass transportation systems like trains. The bottom line is that you just don't run those systems with no tolerance to failure because the result is that a lot of people die.

But... if it is indeed the case that the train's signals are not failure safe, then the signals should be upgraded so they become driver-failure safe, and then we should ask exactly who is responsible for the gross omission and make sure they are held accountable for murder by negligence.

And by the way, this does not make me feel any better:

Tim Smith, state chairman of the Brotherhood of Locomotive Engineers and Trainmen, a union representing engineers and conductors, said issues that could factor into the crash investigation could be faulty signals along the track or engineer fatigue.

He said engineers in California are limited to 12 hours a day running a train, although that can be broken up over a stretch as long as 18 hours.

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